Spring break in a warm, sunny place like Cancun may seem like a great change of scenery for students, but they may be at risk for cancer later, said Dr. Gavin Robertson, assistant professor of dermatology at the Hershey Medical Center.
"Coming from where we are in the winter and going down south, people's skin isn't acclimated to such intense sunlight," he said. "People usually aren't thinking about the sun, but we should always be concerned."
More than one million cases of non-melanoma skin cancer are diagnosed every year in the United States, according to the American Cancer Society. Melanoma, the most serious type of skin cancer, will account for about 54,200 cases of skin cancer in 2003 and most of the 9,800 deaths due to skin cancer each year. Skin cancer is one of the most common cancers, accounting for nearly half of all cancers in the United States. If detected early, it also is very curable, with a survival rate of 89 percent.
Skin cancer has been linked to the number of sunburns that occur during the teenage years, Robertson said.
"Once the damage happens, it stays with you," he said. "The damage adds up. Studies show that 80 percent of the skin damage in your entire life occurs in the first 18 years."
There are two main types of ultraviolet (UV) light -- UVA and UVB, said Dr. John Messmer, associate professor of family and community medicine at the medical center.
UVA causes aging and wrinkles by damaging the support proteins in the skin. It is helpful because it causes the skin to produce vitamin D, which is essential for healthy bones, said Margherita Cantorna, assistant professor of nutrition. If vitamin D cannot be produced through the skin, as in the case of little exposure to sunlight in different seasons and latitudes, it can be acquired through only a few foods, such as milk (three to four glasses), supplements and oily fish, such as salmon.
"Right now, in the winter, you don't make much, even if you're out in the sunlight," she said. "But when the sunlight is stronger, it only takes 10 to 15 minutes on the face and hands to make what you need. You could get enough just by walking to your car or before you put on sunscreen."
To produce vitamin D, sunscreen cannot be worn, because it blocks the UV light. But since the exposure time is short, people should not get sunburned.
"People with more pigments need to be out in the sun longer to make the same amount of vitamin D," Cantorna said. "But if you get sunburned, it's obviously too much."
UVB causes suntans and sunburns by penetrating the skin, Robertson said. Deeper skin cells, called melanocytes, respond to sun exposure by producing melanin (pigment).
More pigment produces a tan, which blocks UVB. However, sunburn occurs with prolonged exposure to the sun after a period of avoiding it and will substantially damage the DNA of the melanocytes. They then mutate and divide, increasing the risk of melanoma with each sunburn.
Although people with more pigment, including blacks, do have much lower rate of skin cancer, they are still at risk, Robertson said.
"They can get it in areas of lighter pigment, such as the palms of the hands, feet and around the eyes," he said.
Preventing sunburn is the best way to avoid skin cancer, since not much can be done after getting sunburned, Robertson said. Here are some tips:
Sunscreen
Apply at least 30 minutes before going out, Robertson said. Cover area thoroughly and reapply every few hours, especially after swimming and then toweling off.
"Sunscreen has the same function as melanin, but it's a man-made chemical," he said.
Sunscreen should be at least 30 spf (sun protection factor) which blocks out 97 percent of UV rays, Robertson said.
"It doesn't matter what type: cream, foam, lotion, etc.," Robertson said. "Some are less oily and greasy. It all depends on the marketing and packaging, but whatever product gets people to put it on is good."
Sunglasses
UV light reflecting from snow, water and sand can also damage eyes and cause ocular melanoma, Roberton said. Choose a pair that blocks UVA and UVB rays 100 percent and covers the whole eye area.
Darker glasses and certain colored lenses are not necessarily better because UV protection comes from an invisible chemical applied to the lenses.
Clothing
Darker, coarser clothing absorbs more UV light than lighter see-through clothes, Robertson said. Some clothing now list their ability to absorb UV light.
Wear a hat
A hat with a three- to four-inch brim is ideal, Robertson said. Many skin cancers are found on the scalp, along the hairline, on the ears and on the neck, because people neglect to protect those areas.
Time of day
Try to limit the amount of time outside during the parts of the day when sunlight is most intense, Robertson said. From 9 a.m. to 3 p.m. is when the sun is most directly overhead. Another way to gauge the strength of the sun is the length of a person's shadow -- if it is less than full length, the sun is too strong.
See a dermatologist every year
"A dermatologist can check you from head to toe for moles," Robertson said. "They can catch any possibly cancerous ones and cut them out before they become more of a problem."
